At present, collaboration between a 3rd Generation Partnership Project (3GPP) network and a non-3rd Generation Partnership Project network becomes a focus of current research. For example, collaboration between a cellular network and a wireless local area network (WLAN) network enables user equipment (UE) to perform, at the same time when working in an LTE network, a service by accessing the WLAN network through a wireless local area network access point (WLAN AP). For example, the cellular network is a network whose standard is Long Term Evolution (LTE), Global System for Mobile Communications (GSM), Code Division Multiple Access (CDMA), or the like.
In the prior art, a WLAN AP obtains, in a WLAN network by contending, a resource for transmitting downlink data, and UE obtains, in a WLAN network and by contending, a resource for transmitting uplink data. In an example, UE sends uplink data (including an uplink data frame and/or an uplink management frame), and a contention process is: when sensing that a channel is in an idle state, the UE first waits for an inter frame spacing (IFS), then selects a random backoff time from zero to a contention window (CW) to avoid a collision, and starts a timer at the same time when selecting the random backoff time; or if a channel is in a busy state, the UE waits. In the idle state, when a timing time of the timer progressively reduces to zero, the UE starts to transmit the uplink data if the channel is still in the idle state. In this process, a collision may occur if multiple UEs select a same random backoff time. After the collision occurs, the UE continues to contend for a resource after doubling the CW (the CW is increased at most to a maximum value of the CW). A data loss occurs when a quantity of retry times exceeds a maximum quantity of times allowed. If many UEs send uplink data, multiple UEs select a same random backoff time because of backoff time selection randomness, causing a large increase in a probability that an uplink data collision occurs. Consequently, service quality cannot be ensured.